It has already been proposed to this effect to form on the surface of a liquid bath (in general water) floating decorative designs which are picked up on various supports onto which they fix. Among the known processes, mention is made in particular of that described in French Patent No. 1 137 346, applied for on 16 June 1954 in the name of Jean-Charles SEAILLES. In this patent, the specially described is that in which the decoration floats and has to be incorporated in a material which may impregnate it following its deposition on a suitable support. In all of these known techniques, the pigments, colours and inks are first put in suspension or in solution in liquids, such as oils, varnishes, solvents, etc., which are then poured onto the water, creating at its surface a film which is often of an oily consistency and in which chance plays the main role in the final distribution of the colours and gives an image of action painting to the decoration obtained. In other words, the known methods of decoration by flotation do not in any way make it possible to obtain on the water a film which carries predetermined lines, such as those of a drawing or a precise image, and even less to distribute in a deliberate fashion the colours (as is done in lithography, screen printing, etc.).